What should you know about sunlight hives?

Hives can appear quickly on exposed skin as raised patches or welts that itch, sting, or change shape. They may fade as the trigger stops, but new areas can appear with further exposure. Deeper swelling around the eyes, lips, hands, or throat is called angioedema and needs particular attention. A clinician may distinguish sunlight-triggered hives from another form of urticaria by asking when the welts start, how long they last, and what else touched or entered the body.

Get out of direct sunlight and cover exposed skin with clothing or shade. Keep the area cool and avoid rubbing or scratching. Photographing the welts while they are present can help a clinician understand a short-lived episode. A healthcare professional may discuss an oral antihistamine and whether a supervised plan is appropriate for future exposure. Do not experiment with deliberate sun exposure to test the reaction.

Call emergency services for trouble breathing, wheezing, dizziness, collapse, or swelling of the tongue or throat. Seek prompt medical advice for rapidly spreading welts, facial swelling, repeated episodes, or symptoms that continue after leaving sunlight. Recurrent reactions deserve assessment even when each individual welt fades.

Ask whether your symptoms fit sunlight-triggered urticaria, whether an antihistamine plan is suitable, and how to protect your skin during necessary outdoor activities. Ask how to recognise angioedema or a more serious allergic reaction.